The present invention relates to a method for assembling and adjusting a brake of the type of those which use a drum of given inside diameter and which comprise: a backplate; two shoes, each of which exhibits a lower end and an upper end; return springs urging these shoes towards one another; a wheel cylinder secured to the backplate and capable of moving the upper ends of the shoes away from one another; an anchoring unit secured to the backplate, of given width, and on which the lower ends of the shoes rest; and a strut of adjustable length limiting the extent to which the shoes come together.
A brake of this type is described, for example, in U.S. Pat. No. 4,903,800 which is incorporated herein by way of reference.
According to the conventional art, it is common practice to assemble and adjust the whole drum brake at the factory, then to mount the complete brake on the vehicle.
In order to do this, each of the components of the brake is mounted, at the factory, on the backplate, and the backplate is then fixed to the chassis of the vehicle, the wheel cylinder moreover being connected to the hydraulic braking circuit of this vehicle.
Such a method is particularly inappropriate as far as overhauling a brake, already in place on a vehicle, is concerned, not only because some of the components of the brake to be overhauled, and particularly the backplate, are systematically replaced although they have not undergone any wear, but above all because the mounting of a complete brake is a long and tricky operation.
It is already known, in order to alleviate these drawbacks, to replace, when overhauling a brake, only those components which seem worn or most worn.
Such a practice however leads to a significant risk that the overhauled brake might not exhibit optimum operational and safety characteristics owing to the difficulties that the separate mounting of the components of the brake on the backplate when the latter is secured to the vehicle, and the adjustment of the brake thus mounted involve.